1. Technical Field
The present invention relates to a liquid ejecting head that ejects liquid and a liquid ejecting apparatus. In particular, the invention relates to an ink-jet recording head that ejects ink and an ink-jet recording apparatus.
2. Related Art
Some recording apparatus includes an ink supply member that has a liquid flow channel, which is the flow channel of ink supplied from an ink container such as an ink cartridge to a recording head. Besides the liquid flow channel, the ink supply member includes, for example, a pressure adjusting means. The pressure adjusting means adjusts the pressure of ink supplied to the recording head to ensure that it is within a predetermined range. An example of such a pressure adjusting means is disclosed in JP-A-2007-210124. The pressure adjusting means disclosed therein includes a pressure reception portion, an actuation lever, and a valve member. The pressure reception portion is made of a flexible material as a part of the wall surface of the liquid flow channel. The position of the pressure reception portion changes due to elasticity as the internal pressure of the liquid flow channel changes. In the process of its elastic deformation, the pressure reception portion applies a pressing force to the actuation lever. The valve opens and closes as a result of the operation of the actuation lever.
In the recording head disclosed in JP-A-2007-210124, a part of the wall surface of the liquid flow channel is formed as the pressure reception portion that is made of a flexible material. Therefore, the shape of the pressure reception portion is determined depending on the shape of the liquid flow channel. For this reason, if a plurality of liquid flow channels having different lengths is formed in the ink supply member, and if a part of the wall surface of each of the plurality of liquid flow channels is formed as a pressure reception portion, it follows that the shapes of the pressure reception portions differ from one liquid flow channel to another. Since the shapes of the pressure reception portions differ from one liquid flow channel to another, the amount of a change in the position of the pressure reception portion that is caused by the change in the internal pressure of the liquid flow channel also differs from one liquid flow channel to another, which results in variation in the degree of the opening and closing of the valve from one liquid flow channel to another. Consequently, since the pressure levels of ink supplied to the recording head differ from one liquid flow channel to another, there is a risk of poor printing.
On the other hand, if the liquid flow channels have to be formed in such a manner that the pressure reception portions have a uniform shape, the freedom of design of the liquid flow channels is sacrificed. For example, in a structure in which filter chambers that are in fluid communication with liquid flow channels are arranged in a matrix for the purpose of reducing the size of a member in which flow channels inclusive of the filter chambers are formed, it is inevitable that the length of a certain liquid flow channel that is in fluid communication with a certain filter chamber that belongs to a certain row is not the same as the length of another liquid flow channel that is in fluid communication with another filter chamber that belongs to another row. For this reason, it is practically difficult to design each of the liquid flow channels in such a manner that the pressure reception portions have a uniform shape.